Shelf



FIG. 1 is a perspective view showing the new design for a shelf;

FIG. 2 is a right side view thereof, a left side view being a mirror image thereof;

FIG. 3 is a front view thereof;

FIG. 4 is a rear view thereof;

FIG. 5 is a top view thereof; and,

FIG. 6 is a bottom view thereof.

The broken lines in the drawings are shown for illustrative purposes only and form no part of the claimed design. In addition, the surface shading illustrated in the drawings is provided merely to highlight the contour of design; it is not intended to be illustrative of texture or gloss. 

CLAIM The ornamental design for a shelf, as shown and described. 